Clamping device

ABSTRACT

A clamping device has an actuator that moves linearly and is actuated by a drive. A pivoting clamping element is operatively connected, via a toggle lever mechanism, with the actuator. The toggle lever mechanism includes a drive-side adapter and a hand lever-side adapter. The drive side adapter and hand lever side adapter can be adjusted relative to one another to define an opening angle of the clamping element. One of the adapters has a profiled bar extending in a direction of actuation. The other adapter has an insertion region to accommodate the bar. A fixing element is provided in one of the adaptors to define the location of the adapters relative to one another. The fixing element can be clamped against the profiled bar and also against an insertion region.

The invention relates to a clamping device according to the preamble of claim 1.

A clamping device of the kind described in the preceding is known from DE 202 09 237 U1. This comprises an actuator that is able to move linearly and may be actuated by a drive (typically a pneumatic cylinder), and which is designed to be operatively connected via a toggle lever mechanism to a pivotably mounted clamping element (also called a clamping arm), and which has an adapter part on the drive side and an adapter part on the toggle lever-side, wherein said adapter parts are designed to be displaceable relative to one another via a gearing arrangement and a tensioning screw directed toward one another in order to define an opening angle of the clamping device.

The object underlying the invention is to improve a clamping device of the kind described in the introduction.

This object is solved with a clamping device of the type described in the introduction by the features listed in the characterizing part of claim 1.

According to the invention, therefore, it is provided that one of the adapter parts comprises a profiled bar extending in the direction of actuation, and the other adapter part has an insertion region in the form of a cavity for accommodating the bar, wherein for purposes of defining the location of the adapters relative to one another a fixing element is provided that may be clamped both against the profiled bar and against the insertion region.

In other words, the solution according to the invention is distinguished by the fact that the one adapter part is designed such that it is able to be inserted in the other adapter part, or in a cavity in the other adapter part, and so that its position may be fixed. This essential feature results in overall distribution of forces in both components, which are exposed to high loads, together with improved adjustability of the opening angle, which will be explained in greater detail in the following.

Other advantageous refinements will be apparent from the dependent claims.

In the following, the clamping device according to the invention and the advantageous refinements thereof according the dependent claims will be explained in greater detail with reference to the diagrammatical representation of two embodiments thereof.

In the drawing:

FIG. 1 shows a cross-section of a clamping device with the adapter part designed according to the invention;

FIG. 2 shows a side view of the adapter part of FIG. 1 on its own;

FIG. 3 shows a cross-section of the adapter part of FIG. 1 on its own; and

FIG. 4 shows a cross-section of another embodiment of the clamping device according to the invention, in which the bar is arranged on the adapter part on the toggle lever side and the insertion area is arranged on the adapter part on the drive side.

The clamping device illustrated in FIGS. 1 and 4 comprises an actuator 2 that is able to move linearly and may be actuated by a drive 1 (a pneumatic or hydraulic drive unit with a piston and piston rod), and which is connected directly to a piston rod of drive 1 and connected operatively to a pivotably mounted clamping element 3 (preferably a “clamping arm”) via a toggle lever mechanism. If viewed in a little more detail, it is provided that adapter part 2.2 and 2.1 on the toggle lever side is designed so as to be connected in articulated manner to a tab 14, which tab 14 is in turn connected in articulated manner to lever arm 15, and lever arm 15 is connected in non-rotating manner to a pivoting shaft of clamping element 3. Actuator 2 further has one adapter part 2.1 on the drive side thereof and one adapter part 2.2 on the toggle lever side thereof, wherein both adapter parts are designed to be movable toward one another so as to fix an opening angle of clamping element 3.

Given the above, an essential feature for the clamping device according to the invention, as is also indicated in FIGS. 2, 3 and 4, is that one of the adapter parts 2.1 comprises a profiled bar extending in the direction of actuation, and the other adapter part 2.2 comprises an insertion region 5 that at least partly surrounds bar 4 for accommodating bar 4 and for completely surrounding bar 4, wherein a fixing element 6 is provided and may be clamped both against profiled bar 4 and against insertion region 5 in order to fix the position of adapter parts 2.1, 2.2 relative to one another.

In this context, it is particularly preferably provided that fixing element 6 is designed as a ring that is penetrated by bar 4 and has an inner and an outer wall, wherein the inner wall has profiling 7 that matches profiled bar 4 in form fitting manner, and the outer wall has a plurality, preferably four to eight, planar surfaces 8. In this case, fixing element 6 is particularly preferably in the form of a screw nut or is a screw nut and is also constructed so as to completely surround profiled bar 4, wherein profiling 7 of the inner wall as well as the profiling of bar 4 are also particularly preferably constructed as internal threads with no pitch. In this context, the term “with no pitch” is understood to mean a thread with a “zero” pitch—and so not a true thread per se but simply a gearing arrangement that looks like a thread.

In order to be able to fix the position of the two adapter parts 2.1, 2.2 relative to one another simply, it is further preferably provided that the diameter of bar 4 in the region of its profiling is always designed to be smaller than a diameter defined by the inner wall of fixing element 6. In the embodiment of FIGS. 1 to 3, fixing element 6 is also arranged in an insertion opening 9 on the adapter part 2.2 on the toggle lever side, and is secured therein against shifting in the primary axial direction of actuator 2. In the embodiment of FIG. 4, fixing element 6 is arranged in an insertion opening on the drive-side adapter part 2.2. As a result of the two diameters, therefore, fixing element 6 is thus designed so as to be displaceable, or offsettable, transversely but not longitudinally with regard to bar 4.

In addition, an adjustment element 10 is also preferably provided on the adapter part 2.2 on toggle lever side (FIGS. 1 to 3) and on the drive side (FIG. 4) to shift fixing element 6 transversely to the main axial direction of actuator 2, and towards profiled bar 4. Accordingly, this adjustment element 10 is designed as a screw, particularly a grubscrew, guided in aligned thread 11 oriented transversely to the bar 4, provided on adapter part 2.2. Moreover, an aperture 18 that is closable (with a cap element) if necessary is provided on housing 17 of the clamping device for actuating adjustment element 10 from outside the clamping device.

As is known from DE 10 2009 054 153 A1, an end position encoder 12, 13 is also provided on each adapter part 2.1, 2.2. These end position encoders cooperate with corresponding sensors to obtain the adjustment position of the clamping arm. According to one particularly preferred embodiment of the solution of the invention (see FIGS. 1 to 3), the fixing element 6 is arranged between the two end position encoders (12, 13) and/or is arranged at the end position encoder 13 of the adapter 2.2 on the toggle lever side.

Adjustment of the clamping device according to the invention is carried out as follows:

The starting point of the consideration are adapter parts 2.1 2.2, which are fixed with respect to one another. In order to change the opening angle of clamping element 3, first the cap is removed from aperture 18. Then, the grubscrew (adjustment element 10) which is preferably constructed as an inner inbuss, internal with is oriented so that its actuation side faces toward aperture 18, is taken out with an Allen key. The result of this is that the profiling of fixing element 6 is disengaged from the profiling of bar 4, that is to say the two adapter parts 2.1, 2.2 can now be displaced lengthwise with respect to one another. Once the desired position has been reached, fixing element 6 is tightened against bar 4 again by tightening adjustment element 10, so that the two adapter parts 2.1, 2.2 are fixed against one another again. Finally the cover is re-inserted in aperture 18 and the adjustment of the opening aperture is complete.

REFERENCE LIST

-   1 Drive -   2 Actuator -   2.1 Adapter part -   3.2 Adapter part -   3 Clamping element -   4 Bar -   5 Insertion region -   6 Fixing element -   7 Profiling -   8 Surface -   9 Insertion opening -   10 Adjustment element -   11 Thread -   12 End position encoder -   13 End position encoder -   14 Tab -   15 Lever arm -   16 Pivoting shaft -   17 Housing 

1-10. (canceled)
 11. A clamping device comprising: an actuator that moves linearly and is actuated by a drive; a pivoting clamping element is operatively connected, via a toggle lever mechanism, with the actuator; the toggle lever mechanism includes a drive-side adapter and a hand lever-side adapter, the drive side adapter and hand lever side adapter can be adjusted relative to one another to define an opening angle of the clamping element; one of the adapters has a profiled bar extending in a direction of actuation, the other adapter has an insertion region to accommodate the bar; a fixing element is provided in one of the adaptors to define the location of the adapters relative to one another, the fixing element can be clamped against the profiled bar and also against an insertion region.
 12. The clamping device according to claim 11, wherein the fixing element is designed as a ring penetrated by the bar with an inner and an outer wall, the inner wall has profiling that matches up with the bar in a form fitting manner and the outer wall has a plurality of plane surfaces.
 13. The clamping device according to claim 12, wherein a diameter of the bar in its profiling region is always smaller than a diameter defined by the inner wall of the fixing element.
 14. The clamping device according to claim 11, wherein the fixing element is arranged in an insertion opening on the toggle lever-side adapter and is secured in the latter against any displacement in the main axial direction of the actuator.
 15. The clamping device according to claim 11, wherein the fixing element completely encloses the bar.
 16. The clamping device according to claim 11, wherein an adjustment element is provided on the toggle lever-side adapter, the adjustment element displaces the fixing element transverse to the main axial direction of the actuator and against the profiled bar.
 17. The clamping device according to claim 16, wherein the adjustment element is a screw, particularly a grub screw, guided in a thread, oriented transverse to the bar, provided in the toggle lever-side adapter.
 18. The clamping device according to claim 11, wherein an end position encoder is provided on each adapter and the fixing element is arranged between the two end position encoders.
 19. The clamping device according to claim 11, wherein the fixing element is arranged on an end position encoder of the toggle lever-side adapter.
 20. The clamping device according to claim 11, wherein an insertion region completely encloses the bar. 